||Complicated, isn't it?
As far as I know, the flag honors and who salutes when is still pretty much the same. The ranks are not. (Nor are they quite the same as in World War 2.) The Officer ranks have not changed, but the Warrant-Officer ranks sure have. By 1969 there were four W-O ranks. Circa 1990 a fifth W-O rank was added. When I was a military brat in 1950 Enlisted rank stopped at E-8 for both Master Sergeant and First-Sergeant. Sometime later the rank E-9 was added for Sergeant-Major and Command Sergeant-Major. Today, AFAIK, E-4 can be either Specialist, or Corporal. But, sometime during the Cold War, Specialist rank could be from E-4 to E-9. I served as a Specialist E-5 (called "Spec-5") beginning in 1972. Specialist ranks were phased out from the top down until only the E-4 remains.
If you are curious, I'm sure current information is easily found on Department of Defense web-sites.